1. Field of the Invention
The present invention generally relates to a system for receiving and processing a GPS signal and a traffic information signal, and more particularly to a GPS system for receiving and processing a GPS signal and a traffic information signal, wherein a processor of a GPS receiver rotationally stores the GPS signal and the traffic information signal into a buffer and then transmits the stored signals to a storage device, in order, for displaying the information.
2. Description of the Related Art
Presently, a traffic condition has improved significantly to provide more convenience and quality to our every day activities. Accordingly, a concept of global village is created. For saving energy, precious time and increasing efficiency, a system to accurately locate a person or object in a large range and to communicate thereto without any limit of time and location is very essential. Accordingly, a global positioning system (GPS) has been developed to accurately provide the information of the latitude and the longitude to enable the users all around the world know their exact location.
Furthermore, there are two major purposes of the GPS system. The first purpose is to locate, retrieve exact location information by referring to the location information transmitted by the satellite, and the second purpose is to synchronize signal in the internet. Because the satellite provides a time signal, and if the world wide internet system can receive this time signal, the internet system will have a stable resource for the synchronized signal, and most of the devices may be gradually designed to rely on this simple and stable method for receiving the synchronized signal.
Generally, a GPS receiver receives signals from a plurality of satellites corresponding to the positions of objects or persons, and the time signal can be chosen from a signal with the best quality. The GPS system is mostely used in the transportation industry. GPS receiver is installed in a car, airplane or a ship to receive the satellite signal to enable the user to learn the exact location for various services, for example, navigation, SOS, road rescue, security and so on.
As the semiconductor technology is well developed, the overall cost may be reduced. Thus, the car GPS is widely used, and the use of GPS system in the car has become the major purpose of the GPS system. Commonly, the user uses the GPS system with the car LCD display or the PDA for retrieving map signal and navigation status information.
Furthermore, the FM radio message system is another appliance of the traffic message channel (TMC), which broadcast the traffic and weather information to guide the user to take a proper route to arrive at the destination. The traffic information is being updated on real time basis, for example accident, traffic and other information, so that the user may choose the best route to arrive at the destination. Therefore, the TMC provides the traffic information on real time basis to the users on the road and the TMC is different from the roadside traffic news bulletin board.
When using the TMC and the GPS receiver in the car navigation, the TMC receives the real time traffic information and transmits the GPS signal and traffic signals to LCD display, PDA or car navigator where it is displayed. Referring to FIG. 4, the conventional terminal device A comprises a receiving interface A1 to receive signals from a GPS receiver C1 and a traffic information receiver C2. When the receiving interface A1 simultaneously receives GPS and traffic signals, a processor A2 in the terminal device A encodes the GPS and traffic signals and then wraps it into a packet as a signal set which is then transmitted to a receiving interface B1 of a portable host B through a transmission interface A3 of the terminal device A. Next, a memory program B2 in the portable host B decodes and restores the signal set into the GPS signal and traffic information so that the portable host B displays the map represented by the GPS signal and traffic information. Even though the conventional art provides the GPS signal and the traffic information signal to the portable host B, but there are still more defects, which are described as follows.                1. The conventional terminal device A simultaneously receives the signals transmitted by the GPS receiver C1 and the traffic information receiver C2, which is then encoded into a packet for converting signals into a signal set and then transmitted to the portable host B where it is decoded. Because, the GPS signal and traffic information signal are both continuously simultaneously transmitted, thus often packaging and decoding processes occupies the memory capacity and the system resource of the terminal device A and the portable device B, and therefore the overall transmission quality is adversely affected.        2. When the terminal device A simultaneously receives the GPS signal and traffic information signal, interference between the GPS signal and the traffic signal may easily occur and cause instability in signal transmission, or the information may be overwritten and become invalid.        
Therefore, how to overcome the above defects is an important issue for the manufacturers in the field.